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Computer Modeling in engineering & Sciences 2024年第3期138卷 2129-2157页

作者： Lianghao Hua Jianfeng Zhang Dejie Li xiaobo xi School of Mechanical engineering Yangzhou UniversityYangzhou225009China college of Intelligent Manufacturing Yangzhou Polytechnic InstituteYangzhou225009China School of Automation Nanjing University of Aeronautics and AstronauticsNanjing211106China

With the increasing prevalence of high-order systems in engineering applications, these systems often exhibitsignificant disturbances and can be challenging to model accurately. As a result, the active disturbance rejectioncontroller (ADRC) has been widely applied in various fields. However, in controlling plant protection unmannedaerial vehicles (UAVs), which are typically large and subject to significant disturbances, load disturbances andthe possibility of multiple actuator faults during pesticide spraying pose significant challenges. To address theseissues, this paper proposes a novel fault-tolerant control method that combines a radial basis function neuralnetwork (RBFNN) with a second-order ADRC and leverages a fractional gradient descent (FGD) *** integrate the plant protection UAV model’s uncertain parameters, load disturbance parameters, and actuatorfault parameters and utilize the RBFNN for system parameter identification. The resulting ADRC exhibits loaddisturbance suppression and fault tolerance capabilities, and our proposed active fault-tolerant control law hasLyapunov stability implications. Experimental results obtained using a multi-rotor fault-tolerant test platformdemonstrate that the proposed method outperforms other control strategies regarding load disturbance suppressionand fault-tolerant performance.

关键词： Radial basis function neural network plant protection unmanned aerial vehicle active disturbance rejection controller fractional gradient descent algorithm

Enhanced red luminescence of Ca_(3.Si_(2−x)M_(x)O_(7):Eu^(3.)(M=Al,P)phosphors via partial substitution of Si^(4.) for applications in white light-emitting diodes

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Rare Metals 2024年第2期43卷 736-748页

作者： Yu-Hao Ma xi Gao Wen-Tao Zhang Zhen-Rui Yang Zhou Zhao Chen Qu college of Materials and Chemistry and Chemical engineering Chengdu University of TechnologyChengdu610059China State Key Laboratory of Geohazard Prevention and Geoenvironment Protection Chengdu University of TechnologyChengdu610059China International Advanced Energy Science Research and Education Center Graduate School of Energy ScienceKyoto UniversityYoshida-HonmachiKyoto606-8501Japan

A red-emitting phosphor Ca_(2.91)Si_(2)O_(7):0.09Eu^(3.) with partial Al^(3.)/P^(5+) substitution on Si^(4.) was synthesized via a simple solid-state method,and the effects of the introduction of the M^(3./5+)(M=Al,P)ions on the crystal structure and photoluminescence performance of Ca_(2.91)Si_(2−x)M_(x)O_(7):0.09Eu^(3.) phosphors were *** X-ray diffraction(XRD),energy-dispersive X-ray spectroscopy(EDS),and X-ray photoelectron spectroscopy(XPS)results revealed that the structure of Ca_(3.Si_(2)O_(7) remained the same after the introduction of Al^(3.) and P^(5+) *** characteristic emission of Eu^(3.)-doped Ca_(3.Si_(2−x)M_(x)O_(7) phosphors exhibited two main peaks at 617 nm(red)and 593.nm(orange)under excitation at 3.4.nm,which originated from the^(5)D_(0)→^(7)F_(2)and^(5)D_(0)→^(7)F_(1) electron transitions of Eu^(3.) *** the partial substitution of Al^(3.) and P^(5+),the red emission intensities of the Ca_(2.91)Si_(2)O_(7):0.09Eu^(3.) phosphors were significantly enhanced by 1.88-and 1.4.-fold,respectively,which is attributed to the crystal-field effect around Eu^(3.).Meanwhile,the luminescence intensities of the Ca_(2.91)Si_(1.96)Al_(0.04.O_(7):0.09Eu^(3.) and Ca_(2.91)Si_(1.94.P_(0.06)O_(7):0.09Eu^(3.) phosphors at 210℃ were 79.3.%and 77.53.of those at 3.°C,respectively,indicating their excellent thermal ***,the as-prepared Ca_(2.91)Si_(1.96)Al_(0.04.O_(7):0.09Eu^(3.)and Ca_(2.91)Si_(1.94.P_(0.06)O_(7):0.09Eu^(3.) red-emitting phosphors were combined with a near-ultraviolet chip of 3.5 nm to fabricate red-light-emitting diode(LED)and white(w)-LED devices with excellent chromaticity *** summary,Al^(3.)/P^(5+)-substituted Ca_(2.91)Si_(2)O_(7):0.09Eu^(3.) can serve as red-emitting phosphors for applications in w-LEDs.

关键词： Ca_(3.Si_(2)O_(7) Red-emitting phosphor Structure substitution Luminescence enhancement Crystal-field effect White light-emitting diode

Facile synthesis of W-Mo bimetallic oxides with high adsorption properties from secondary resources

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Tungsten 2024年第4期6卷 806-820页

作者： Jia-Li Cheng Yang-Si Liu xiao-Li xi Zuo-Ren Nie Collaborative Innovation Center of Capital Resource-Recycling Material Technology College of Materials Science and Engineering Beijing University of Technology National engineering Laboratory for Industrial Big-Data Application Technology Beijing University of Technology Key Laboratory of Advanced Functional Materials Ministry of Education Beijing University of Technology

A simple solvothermal method was used to obtain W-Mo bimetallic oxides from W-Mo alloy scrap,and pure metal powders were also used as the raw materials to simulate *** products had a sea urchin-like structure with abundant oxygen vacancies and the products prepared at low temperatures forms a sosoloid resembling orthorhombic *** WMo bimetallic oxide prepared at the reaction temperature of 120 ℃ exhibited excellent selective adsorption performance for methylene blue（MB）,which the adsorption rate of MB reached 99% in 12 min and the adsorption rate reached 90% after6 adsorption *** the W-Mo molar ratio is 1:3.the maximum adsorption capacity of sample for MB can reach11{3. mg·*** adsorption process followed the Langmuir and pseudo-second-order models,which is surface-controlled monolayer *** experimental results show the feasibility of preparing W-Mo bimetal oxide products from pure materials and *** process is simple and effective,which offered a potential approach for secondary resource recycling and reusing.

关键词： Oxygen vacancy Selective adsorption Solvothermal W–Mo alloy scrap W–Mo bimetallic oxide

Al-modified yolk-shell silica particle-supported NiMo catalysts for ultradeep hydrodesulfurization of dibenzothiophene and 4.6-dimethyldibenzothiophene:Efficient accessibility of active sites and suitable acidity

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Petroleum Science 2024年第1期21卷 654-666页

作者： Ke Yu Wei-Min Kong Zhen Zhao Ai-Jun Duan Lian Kong xi-Long Wang State Key Laboratory of Heavy Oil Processing China University of PetroleumBeijing102249China Institute of Catalysis for Energy and Environment College of Chemistry and Chemical EngineeringShenyang Normal UniversityShenyang 110034LiaoningChina

Yolk-shell SiO2 particles(YP)with center-radial meso-channels were fabricated through a simple and effective ***-containing YP-supported NiMo catalysts with different Al amounts(NiMo/AYP-x,x=Si/Al molar proportion)were prepared and dibenzothiophene(DBT)and 4.6-dimethyl-dibenzothiophene(4.6-DMDBT)were employed as the probes to evaluate the hydrodesulfurization(HDS)catalytic *** as-prepared AYP-x carriers and corresponding catalysts were characterized by some advanced characterizations to obtain deeper correlations between physicochemical properties and the HDS *** average pore sizes of series AYP-x supports are above 6.0 nm,which favors the mass transfer of organic *** cavity between the yolk and the shell is beneficial for the enrichment of S-containing compounds and the accessibility between reactants and active *** embedded into the silica framework could facilitate the formation of Lewis(L)and Brønsted(B)acid sites and adjust the metal-support interaction(MSI).Among all the as-synthesized catalysts,NiMo/AYP-20 catalyst shows the highest HDS *** improved HDS activity of NiMo/AYP-20 catalyst is attributed to the perfect combination of excellent structural properties of the yolk-shell mesoporous silica,enhanced acidity,moderate MSI,and good accessibility/dispersion of active components.

关键词： Al-containing yolk-shell silica particles Accessibility Acidity Metal-support interaction Hydrodesulfurization

Low-energy-consumption temperature swing system for CO_(2) capture by combining passive radiative cooling and solar heating

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Green Energy & Environment 2024年第3期9卷 507-515页

作者： Ying-xi Dang Peng Tan Bin Hu Chen Gu xiao-Qin Liu Lin-Bing Sun State Key Laboratory of Materials-Oriented Chemical engineering Jiangsu National Synergetic Innovation Center for Advanced Materials(SICAM)College of Chemical EngineeringNanjing Tech UniversityNanjing211816China

Temperature-swing adsorption(TSA)is an effective technique for CO_(2) capture,but the temperature swing procedure is ***,we report a low-energy-consumption system by combining passive radiative cooling and solar heating for the uptake of CO_(2) on commercial activated carbons(CACs).During adsorption,the adsorbents are coated with a layer of hierarchically porous poly(vinylidene fluoride-co-hexafluoropropene)[P(VdF-HFP)HP],which cools the adsorbents to a low temperature under sunlight through radiative *** desorption,CACs with broad absorption of the solar spectrum are exposed to light irradiation for *** heating and cooling processes are completely driven by solar *** tests under mimicked sunlight using the CACs show that the performance of this system is comparable to that of the traditional ***,under real sunlight irradiation,the adsorption capacity of the CACs can be well maintained after multiple *** present work may inspire the development of new temperature swing procedures with little energy consumption.

关键词： CO_(2)capture Solar heating Passive radiative cooling Temperature swing adsorption

Improvements in energy saving and thermal comfort for electric vehicles in summer through coupled electrochromic and radiative cooling smart windows

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Building Simulation 2024年第8期17卷 1231-1251页

作者： Zhoujie Duan Shuangdui Wu Hongli Sun Borong Lin Pei Ding Tao Cui Jeremy To xi Zhang college of Architectureand Environment Sichuan UniversityChengdu610065China Department of Building Science Tsinghua UniversityBejing 100084China KeyLaboratoryofEco Planning&Green Building MinistryofEducationTsinghua UniversityBeijing100084China State Key Laboratory of Hydraulics and Mountain River engineering Sichuan UniversityChengdu 610065China School of EmergencyManagement Xihua UniversityChengdu 610039China Department of PSVD Mercedes-benz Group China Ltd.Beijing 100102China

In hot climates,the large amount of cooling load in electric vehicle(EV)results in a lot of battery energy consumption,leading the decrease of driving *** the widespread application of windows in EV,the electrochromic glass(EC)shows great prospect in lowering the cooling ***,researches on the application of EC in EV lack the consideration of both passive cooling measures and passenger comfort,which limits the further application of *** this paper,we proposed an idea combining the novel techniques of both electrochromism and radiative *** fluid dynamics(CFD)is modeled to simulate the application of electrochromic and radiative cooling coupled smart windows in hot parking conditions,exploring the improvement effect of the window on the thermal environment,comfort and energy saving of the *** results indicate that,under the intense sunlight with an outdoor temperature of 3.℃,activating the air conditioning to maintain an average interior temperature of 26℃,the coupled windows reduced the cooling capacity of the air conditioning by 762 W compared to regular windows,which can further increase the range of ***,compared to simple electrochromic fully colored glass,the integration of radiative cooling technology can lower the window surface temperature by up to 10.7℃.Moreover,compared to regular windows,the coupled windows lowered the standard effective temperature(SET*)for passengers by approximately 7℃,significantly improving *** research findings are expected to provide guidance for optimizing window design and enhancing the performance of EV.

关键词： electrochromism radiative cooling smart windowel ectric vehicle cabin thermal comfort energy saving

Predictor-corrector interior-point algorithm for linearly constrained convex programming

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Journal of Central South university 2001年第3期13卷 208-212页

作者： LIANG xi-ming (college of Information Science & engineering, Central South {3., {3.sh a 4.0083. China) 1. college of Information Science & engineering Central South University 410083 Changsha China

Active set method and gradient projection method are curre nt ly the main approaches for linearly constrained convex programming. Interior-po int method is one of the most effective choices for linear programming. In the p aper a predictor-corrector interior-point algorithm for linearly constrained c onvex programming under the predictor-corrector motivation was proposed. In eac h iteration, the algorithm first performs a predictor-step to reduce the dualit y gap and then a corrector-step to keep the points close to the central traject ory. Computations in the algorithm only require that the initial iterate be nonn egative while feasibility or strict feasibility is not required. It is proved th at the algorithm is equivalent to a level-1 perturbed composite Newton method. Numerical experiments on twenty-six standard test problems are made. The result s show that the proposed algorithm is stable and robust.

关键词： linearly constrained convex programming predictor corrector interior point algorithm numerical experiment

Synthetically adaptive robust filtering for satellite orbit determination

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Science China Earth Sciences 2004年第7期47卷 585-592页

作者： YANG Yuanxi1 & WEN Yuanlan2 1. xi’an Research Institute of Surveying and Mapping, xi抋’an {3., China 2. college of Aerospace and Material engineering, National {3. of Defense Technology, {4.sha 4.0073. China 1. xi’an Research Institute of Surveying and Mapping 710054 Xi’an China 2. college of Aerospace and Material engineering National University of Defense Technology 410073 Changsha China

The quality of the satellite orbit determination is rested on the knowledge of per-turbing forces acting on the satellite and stochastic properties of the observations, and the ability of controlling various kinds of errors. After a brief discussion on the dynamic and geometric orbit determinations, Sage adaptive filtering and robust filtering are reviewed. A new synthetically adaptive robust filtering based on a combination of robust filtering and Sage filtering is *** is shown, by derivations and calculations, that the synthetically adaptive robust filtering for orbit determination is not only robust but also simple in calculation. It controls the effects of the outliers of tracking observations and the satellite dynamical disturbance on the parameter esti-mates of the satellite orbit.

关键词： satellite orbit, Sage filtering, adaptive orbit determination, robust estimation.

Recent Development of Heat Transfer and Fluid Flow of Supercritical CO2 in Tubes:Mechanisms and Applications

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Journal of Thermal Science 2024年第06期33卷 2274-2298页

作者： ZHANG xirui SHAO Qihan LIU Jian xi Wenxiong LIU Chaoyang SUNDEN Bengt Research Institute of Aerospace Technology Central South University college of Aerospace Science and engineering National University of Defense Technology Department of Energy Sciences Lund University

With the advantages of low cost,excellent ability of heat and mass transfer and easy accessibility to the supercritical point,supercritical CO2has been applied in many engineering devices *** of the sharply-varying thermophysical properties near the supercritical point,heat transfer and flow behavior of supercritical CO2in tubes become complex and have received a lot of research *** main purpose of this paper is to summarize the findings of the published works related to flow phenomena and heat transfer characteristics of supercritical ***,influence parameters related to boundary conditions of supercritical CO2flowing in a smooth tube are ***,commonly-used turbulence and mathematic models dealing with internal flows of supercritical CO2are ***,research works on geometric effects of design parameters,shapes and configurations are *** practical applications of supercritical CO2in recent years are ***,developments and future challenges of supercritical CO2in tubes are analyzed and *** paper provides basic knowledge of heat transfer and fluid flow mechanisms and related practical applications of supercritical CO2in tubes.

关键词： developments and challenges flow behavior heat transfer practical applications supercritical CO2